Gun



O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2. 1919.

1,396,832. Patented Nov. 15, 1921.

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[mi/X7 013, 0//': e/ B. Graham.

O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2.1919.

Patented Nov. 15, 1921.

5 SHEETSS HEEI 2.

I l g O. B; GRAHAM.

GUN.

APPLICATION FILED JULY 2.1919.

Patented Nov. 15, 1921.

5 SHEETSSHEE1 3.

7013 0/IV6/ZB. Gar/701m O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2,1919.

Patented Nov. 15, 1921;

5 SHEETSSHEEI 4-' li magi MN ww RN 0. B. GRAHAM. GUN.

APPLICATION FILED JULY 2,19l9- 1,396,832. Patented Nov. 15, 1921.

5 SHEETS-SHEEI 5.

I @17025; O/A er B 670/9011. J 6/7 m Jim T @111 T Q OLIVER B. GRAHAM, OFCLEVELAND, OHIO, ASSIGNOR TO AUTO-ORDNANCE CORPORA- TION, OF NEW YORK,N. Y., A CORPORATIO1\T OF NEW YORK.

GUN.

Application filed July 2,

To all whom it may concern:

Be it known that I, OLIVER B. GRAHAM, a citizen of the United States,and resident of Cleveland, in the county'of Cuyahoga and State of Ohio,have invented new and useful Improvements in Guns, of which thefollowing is a specification.

This invention relates to firearms and more particularly to an armyrifle operating semi-automatically according to the dis covery disclosedin the patent to Blish, No. 1,131,319, granted March 9, 1915. However,it is to be understood that the invention in certain of its aspects maybe applied to guns of various types-manual, semi-automatic or automatic,but particularly automatic or semi-automaticas e. g. sporting rifles,shot guns, pistols, machine guns, and even heavy guns such as artillerypieces.

The principal objects of the invention are to provide a firearm in whichthe breech closure is automatically locked in closed position directlyin response to the breech pressure acting on the closure while thebreech pressure is at a high value and is automatically unlocked whenthe breech pressure has decreased to a relatively low value, in whichthe firing mechanism is automatically locked in safe condition until thebreech closure is locked, in which the gun is cocked upon the rearwardstroke of the breech closure directly by the force of the breechpressure. in which the breech closure is automatically held in retractedposition after the last cartridge in the cartridge holder has beenfired, in which the firing pin may be retracted only until its forwardface is substantially flush with the forward face of the bolt so as toprevent the primer from blowing back into the firing pin opening. inwhich a striker having a long stroke is arranged to strike the firingpin to fire the gun, in which a safety catch is arranged to lock thestriker out of contact with the firing pin. in which means is providedmanually to unlock and retract the breech closure. and in which improvedmeans is provided to lubricate the contacting surfaces between the.cartridge cases and the firing chamber, and if desired. also between thebullets and the bore of the barrel and between the sliding sur faces ofthe various parts of the breech action.

Other objects are to provide means where- Speciflcation of LettersPatent.

Patented Nov. 15, 1921.

1919. Serial No. 308,228.

by the cartridge magazine may be conveniently and quickly detached withone hand, to eliminate screws and other fastening means which are likelyto Work loose and which render it slow and difiicult to assemble ordisassemble the gun, and generally to simplify, lighten and perfect gunsof the aforesaid character as will hereinafter appear.

In order to disclose the nature of the invention in its various aspectsa specific embodiment thereof has been illustrated in the accompanyingdrawings in which Figure l is a top plan of the gun;

Fig. 2 is a side elevation of the gun;

Fig. 3 is a vertical central longitudinal section of the gun with theparts in position ready to fire, the barrel and stock being broken away;

Fig. 4 is a section on line 4-4 of Fig. 3;

Fig. 5 is a section on line 55 of Fig.

Fig. 6 is a section on line 66 of Fig.

Fig. 7 is a section on line 77 of Fig.

Fig. 8 is a section on line 88 of Fig. 3;

Fig. 9 is a side elevation of the portion of the gun shown in Fig. 3,showin the stock in central section and showing the receiver broken awayabove the broken line 70, the parts being in position ready to fire asin Fig. 10 is a horizontal section on line 1()-1() of Fig. 9;

Fig. 11 is a top plan of the portion of the gun shown in Figs. 9 and 10,showing parts in section and parts broken away on each side of thesection;

Fig. 12 is a view similar to Fig. 3, showing the parts in the positionsthey occupy at the instant of firing;

Fig. 13 is a view similar to Figs. 3 and 12, showing the arts in thepositions they 00- cupy after firing when the bolt is in fully retractedposition, the cartridge lubricating and magazine catching means beingomitted from this figure and also from Fig. 12;

Fig. 13 is a perspective view of the bearing plate for the bolt lock;

Fig. 14 is a perspective view of the bolt stop, ejector and interlockingwasher slightly separated Fig. 15 is a perspective view of parts of thebreech action slightly separated:

Fig. 16 is a perspective view of the bolt lock;

Fig. 17 is a perspective view of parts of the safety catch slightlyseparated;

gig. 18 is a side elevation of the bolt lock; an

Fig. 19 is a cross section of the magazine.

The particular embodiment of the invention chosen for the purpose ofillustration, comprises in general a stock H, a receiver R, a. barrel Athreaded into the forward end of the receiver, a breech bolt B, atrigger guard G, a clip C for securing the forward end of the stock H tothe barrel A, and a rear sight mount w adapted to carry the rear sight uand also to cover the rear portion of the receiver R, the stock andreceiver having alined openings on the lower side of the gun to receivea cartridge magazine CM. Mounted on the forward end of the barrel is afront sight 0, which may be of any suitable construction. The clip C isU-shaped and fits into a depression in the stock H, a screw 2 beingprovided to secure the two ends of the clip together beneath the stock.The clip C is provided on its upper side with a rearwardly extendingshield 3, adapted to cover the opening in the upper side of the forwardend of the receiver R, the shield 3 being formed integrally with theclip and being dovetailed into the receiver as shown in Fig. 4. A sleeveI of asbestos or other suitable insulating material is provided aroundthe rear end of the barrel. this sleeve serving to protect the hand ofthe user from the hotbarrel and also serving to protect the stock fromthe heat of the barrel. The sight mount w slides into guides on thereceiver from the rear as shown in Figs. 7 and 8 and is held in positionby the upright portion of the trigger guard G which extends uplwardlythrough the stock and receiver as s own in Fig. A spring pressed plungera; is provided in the rear end of the receiver to hold the trigger guardin position, a recess m being provided in the stock to give access tothe plunger. The receiver is provided with a tongue 9 which extendsrearwardly in a recess in the bottom of the stock to interlock thereceiver and stock.

The cartridge magazine CM is of the flat elongate type and is formed ofpressed metal. As shown in Fig. 19, the rear portion of the magazine iswider than the forward portion, the length of the wider portion beingsubstantially equal to the length of the portions of the cartridges ofmaximum diameter. The bottom of the magazine is closed by a member 4secured within the lower end of the magazine box in any suitable manner.The central portion of the rear wall of the magazine is pressedoutwardly to form a longitudinal channel and the follower 5 is providedwith a rear projection 6 extending into this longitudinal channel.Interposed between the bottom A and the follower 5 is a compressionspring 7,

adapted to urge the follower 5 upwardly to feed cartridges to the top ofthe magazine to be picked up by the breech bolt in its forward strokes.Instead of extending the full length of the magazine, the spring 7extends only the length of the wider portlon thereof and consequentlyengages the follower only throughout its rearward portion, thereby morecertainly feeding the cartridges in the proper position to be engaged bthe bolt inasmuch as the rearward end 0 the foremost cartridge otherwisemight not be pressed upwardly into the path of the bolt. As shown inFig. 4, the upper end of the magazine is provided with inturned lipsadapted to engage the foremost cartridge and prevent it from beingejected from the magazine by spring 7, the lower side of the bolt beingshaped to move between the inturned lips to pick up the foremostcartridge. A catch 8 is struck up from the left-hand side of themagazine, as shown in Fig. 4. to cooperate with a magazine catch 9 tohold the magazine in position. As shown in Fig. 5, the magazine isprovided near the top with longitudinal slots extending substantiallythe full length of the thicker portion of the magazine to receive thecartridge lubricating rollers 10 and 10' hereinafter to be described.

The mechanism for detachably securin the magazine to the gun comprises asha t 11 (Fig. 9) jourrialed in transverse portions 12 and 13 of thereceiver, an operating handle 14 extending downwardly and to the rightfrom the forward shaft 11 (Fig. 4). and a torsion spring 15 surroundingthe shaft 11 between the bearing 12 and the catch 9, the spring 15 beinganchored at the forward end to the bearing 12 and engaging the outerside of the catch 9 at its rearward end and being so twisted as to urgethe catch 9 inwardly. The forward portion of the shaft is squared asshown in Figs. 4 and 9 and the catch 9 is provided with a square openingfitting over the square portion of the shaft, so that the shaft andcatch are non-rotatably secured together. when the magazine is inserted,the catch 9 snaps beneath the struck-up lip 8 on the magazine and holdsthe magazine in place. In order to detach the magazine, the finger piece14 is pressed upwardly thereby rotating the catch 9 out of engagementwith the lip 8 on the magazine. By virtue of the unique disposition ofthe finger piece it may be engaged by the fore finger to unlatch themagazine in the upward motion of the hand in the act of grasping themagazine to remove same.

The oiling mechanism comprises the reservoir 16 disposed in the bottomof the receiver as shown in Figs. 3, 8 and 9. and oil ducts 17 leadingfrom the forward end of the reservoir to the tubular shafts uponassesses which the lubricating rollers 10 and 10' are mounted, thetubular shafts being journaled at their opposite ends in brackets 18 and18 mounted on the receiver. The brackets 18 and 18' are suflicientlyelastic to permit the rollers to be forced outwardly when a magazine isinserted or removed and to hold the rollers in contact with thecartridges as the cartridges feed therebetween. The tubular shafts uponwhich the rollers 10 and 10 are mounted are provided with perforationsthrough which the oil may flow to the rollers, the rollers being formedof felt or other suitable material through which the oil will permeateto the peripheral surface thereof.

Referring to the breech action, which embodies the more importantaspects of the invention, the movable parts of the breech closurecomprise a bolt B which reciprocates longitudinally-in the receiver, alock L movable obliquely with respect to the bolt to lock the bolt infiring position and movable longitudinally with the bolt when unlocked,an extractor E mounted on the upper side of the belt at its forward end,a firing pin F, slidable along the axis of the bolt, a firing pin springa for yieldingly holding the firing pin in retracted position, a firingpin stop 6 for limiting the rearward movement of the firing pin, astriker Z slidable along the axis of the bolt for striking the firingpin to fire the gun, a cocking sleeve 0 adapted to retain the striker incocked position, and a striker spring (Z for plunging the strikerforwardly against the firing pin when the striker is released from thecooking sleeve.

The bolt B comprises a forward head 27,

a rear body portion 28, and a neck 29 of reduced width joining the headand body together (Figs. 5, 10 and 15). The opposite sides of the body28 are provided with longitudinal grooves 30 and 30 (Figs. 6, 9., 10 and15) adapted to receive the inturned flanges 20 and 20' (Fig. 6) on thereceiver, these flanges serving as supports and guides for the bolt inits reciprocatory movements. The forward face of the head 27 is providedwith a cartridge seat 31 adapted to receive the head of a cartridge. Therear end of the extractor is cylindrical and slides into a socket 33 inthe projection 32 on top of the neck 29 (Fig. 15) and the forward end ofthe extractor hooks over the cartridge seat to prevent the extractorfrom being dislodged (Figs. 3, 12 and 13). Extending the full length ofthe bottom of the bolt is a slot 34 adapted to receive the ejector.

The rear faces 21 and 21' of the lateral portions of the head 27 areinclined at angles of 41 to the vertical and straddling the neck 29 is aU-shaped lock L having lateral portions 22 and 22 whose forward facesare also inclined at angles of 41 to the vertical. The two lateralportions of the lock are integrally joined together at the top by meansof a transverse portion 23. Extending outwardly from opposite sides ofthe lock L are lugs 24 and 24 whose forward and rearward faces areinclined at angles of 45 to the vertical. The oblique rearward faces ofthe lateral portions 22 and 22 of the lock L are inclined to thevertical at the same angle as the lugs, viz., 45. The lateral portions22 and 22 are provided at their lower end with rearwardly extendlngprojections whose upper faces are concave and whose rear faces arevertical, as shown in Figs. 9, 15, 16 and 18. In cooperativerelationship with the lugs 24 and 24 on the lock, channels are providedin the inner faces of the opposite sides of the receiver. These channelscomprise forward oblique portions 25 and 25 and rearward longitudinalportions 26 and 26, the oblique portions 25 and 25' being inclined tothe vertical at the same angle as the lugs 24 and 24, viz., 45. Mountedover the rear faces of the oblique channels 25 and 25' of the receiveris a bearing p-late P of hardened steel or other material adapted towithstand high'pressure, this plate comprising two legs 34 and 34 and atransverse portion 35. (Fig. 13.) The plate P is dovetailed into thereceiver and slides into place from the top. (Fig. 11.) The plate isprovided at the top with a rearwardly extending flange which engages abeveled edge of the receiver to limit the downward movement of the plate(Figs. 13 and 13 The plate is held in place by the" shield 3 (Fig. 13).

As shown in Figs. 3, 10, etc., the firing mechanism is constructed asfollows: The firing pin F is disposed in an axial chamber in 105 thebolt which is of somewhat larger diameter than the shank of the pin. Therear end of the pin is provided with a head which slidingly fits in thechamber'and the forward end of the pin slidingly fits in an opening 110of smaller diameter. The compression spring d surrounds the shank of thepin and presses rearwardly against the head thereof.

A firing pin stop I) is slidingly fitted into a transverse opening inthe bolt immediately 115 in the rear of the firing pin, to limit therearward movement of the firing pin, the stop b having an axial openingto permit the forward end of the striker to pass therethrough intoengagement with the firing pin. The 120 length of the firing pin is suchthat when the rear end thereof abuts against the stop I) the forward endthereof is flush with the forward face of the bolt, whereby the portionof the cartridge primer fitting over the fir- 125 ing pin opening cannever blow back and lodge in the firing pin opening. The lefthand end ofthe stop 6 is beveled as shown in F i 10 for a purpose hereinafter to bedescribed. The striker Z comprises a tubular 130 portion closed at itsforward end and having pins 36 and 37 res ectively extendin forwardlyand rearwar 1y from the close end of the tubular portion (Fig. 3). Theforward pin 36 is adapted to engage the firing pin when the striker isplunged forwardly and the rearward pin 37 extends beyond the open end ofthe tubular portion of the striker and thence through an axial openingin the cocking sleeve 0. The rear end of pin 37 is provided with a hookadapted to hook over the cocking sleeve and the pin 37 is sufficientlyflexible to be sprung downwardly to disengage it from the cockingsleeve. The striker spring 15 surrounds the pin 37 within the tubularportions of the striker and cocking sleeve. A tripper T slides in avertical channel in the rear face of the bolt (Figs. 3 and 10) and isyieldingly held up by tripper spring 6. The rear end of spring 6 istightly fitted into an opening in the under side of hood 38, whichextends rearwardly from the bolt B, and the forward end of the spring 6extends into an opening in the upper end of the tripper T (Figs. 3 and7). The lower end of the tripper is provided with. a hook by which thetripper may be pulled downwardly against the action of spring 6 when thetrigger is pulled. The tripper is provided with a central openingadapted to receive the head of pin 37 so that the in is unhooked fromthe cocking sleeve w en the tripper is pulled downwardly.

The neck 29 of the bolt B is provided with a transverse slot 39extending from the slot for the firing pin stop I) rearwardly to theplane of the forwardend of the bolt body 28. A pair of transmitters Tand T" are disposed on opposite sides of the neck (of the bolt with armsprojecting into the slot. 5, 10 and 15.) The inner ends of the inwardlyprojecting arms are spaced apart so as to permit the pin 36 of thestriker to pass therebetween but so as to extend into the path of theforward end of the tubular body of the striker. When the transmittersare at the forward end of the slot 39 the striker can strike the firingpin but when the transmitters are moved rearwa-rdly in the slot 39 thetubular portion of the striker will strike the inner ends of thetransmitters and prevent the striker from striking the firing pin.Extending rearwardly from the outer ends of the transmitters arecylindrical lugs over which fit the recoil springs Q and Q. These lugsare of sufiicient length to hold the transmitters in proper angularposition transversely of the bolt. The forward faces of the transmittersbear against the rear vertical faces of the lock L and transmit theforces of the recoil springs to the lock and thence to the bolt. Whenthe lock is in uppermost locked position the inner ends of.

the transmitters are at the forward end of the slot 39 in the bolt andwhen the lock is in lowermost unlocked position the inner ends of thetransmitters are at the rear end of the slot 39. The left-handtransmitter T is provided with a forwardly projecting lug 40 whosebeveled inner face engages the beveled end of the firing pin stop 6,whereby if the gun is assembled without the lock L the firing pin stop bwill be pushed to the right until the striker opening therein is out ofalinement with the striker and the gun cannot be discharged as willhereinafter be described more fully.

The recoil springs Q and Q, are disposed in cylindrical channels in theopposite sides of the receiver, as shown in Figs. 6 and 8, and the upperwalls of these channels overhang the springs to such extent as to holdthe springs snugly in the channels throughout their entire length. Thespring channels extend to the rear end of the receiver so that thesprings may be inserted thereinto from the rear.

Fitting in the rear end of the receiver is a buffer mount M which haslateral lugs extending into the spring channels in the receiver to formabutments for the rear ends of the recoil springs. The buffer plunger Nhas a rod extending axially through the buffer and thence through, anopening in the rear end of the buffer mount, the rear end of this rodbeing notched on the u r side as shown in Fig. 3. A buffer key isdisposed behind the buffer mount-to form a back stop for the buffermount, the key fitting into vertical recesses in the opposite sides ofthe receiver both above and below the recoil spring channels as shown inFigs. 3, 7 and 10. The buffer ,key is provided with a slotted opening toreceive the hooked rearward end of the buffer plunger so that the keyalso serves to prevent the plunger from being accidentally displacedfrom the buffer. The buffer key is held down by the sight mount to asshown in Fig. 7. The space within the buffer is filled with rawhide orother suitable shock absorbing material. Extending forwardly from thebuffer plunger is an integral tube which serves to recock the gun whenthe breech closure recoils as will hereinafter be do scribed more fully.

The trigger mechanism comprises a trigger U hooked over a pin in thereceiver at its upper end (Figs. 3, etc.), a trigger bar V hooked over apin in the receiver in its central region, a trigger bar spring m, and atripper pawl X mounted on the forward end of the trigger bar. The upperend of the trigger is bifurcated to receive the rear end of the triggerbar as shown in Fig. 7. The bar V is provided with :1 lug 12 whichprojects into an opening in the bottom of the receiver to prevent thebar from accidentally becoming unhooked from its wardly beneath thetripper hook.

The ejector J and bolt-stop Y are mounted in the bottom of the receiverinterlocked relationship as shown In Figs. 3, 6,

' 12, 13, etc., these parts being shown in perspective in Fig. 14. Thebolt-stop slides down into a vertical opening in the bottom ofthereceiver and the ejector also slides down into position immediately inthe rear of the bolt-stop with the forward portion 41 extendingdownwardly through the opening 42 in the bolt-stop. (Figs. 3, 14, etc.).

The ejector has a rear flange 43 overhang ing a transverse portion ofthe receiver to limit the downward movement of the ejector. Thebolt-stop has a downwardly projecting shank surrounded by a coiledcompression spring 11,. The bifurcated washer V slides forwardly throughthe slot 44 in the bottom of the ejector and straddles the shank of thebolt-stop. The margin of the washer bears against the bottom of thereceiver so as to lock the ejector in position. The spring 92 bearsagainst the lower face of washer W which is provided with a pair ofdepending lugs arranged to prevent the washer from being Withdrawn fromthe bolt-stop and ejector until the upper end of the spring 1?. has beenpressed downwardly below the level of the lugs. 45 of the bolt-stopslides vertically in the space 46 in the ejector, the vertical dimensionof the cross-bar being less than that of the space 46 so that thebolt-stop has a lim ited range of vertical movement. The upper hookedend 47 of the bolt-stop has a vertical rear face adapted to engage theforward end of the bolt when the stop is in uppermost position and holdthe bolt retracted, and the hooked end has a horizontal under faceoverhanging the vertical channel in the rear wall of the magazine whichis adapted to be engaged by the rear end 6 of the follower 5 when themagazine becomes empty. The bolt-stop is normally held down by spring nout of the path of the bolt but when the magazine becomes empty the stopis lifted by the follower into the path of the bolt, whereby the bolt isautomatically held in retracted position after the last cartridge isfired. The lower end of through an opening in the stock so that the Thecross-bar stop may be manually lifted into position to stop the bolt bypressing upwardly on the projecting end of the shank.

The mechanism for manually retracting the bolt comprises a retractor '1'pivotally mounted on top of the bolt by a retractor pin f, a catch j andspring I: being associated with the retractor )in yieldingly to hold theretractor in normal position. The retractor r and pin 7' are shown inperspective in Fig. 15 and the catch j and spring is are shown inperspective in Fig. 17. The forward end of the retractor is bifurcatedand straddles the projection 32 extending upwardly from the neck of thebolt. The handle of the retractor is provided on its under side with alongitudinal recess adapted to receive parts of the safety catch to bedescribed hereinafter. The bifurcated ends of the retractor are providedwith a pair of cam faces 48 and 48' adapted to engage the concave faces49 and 49' of the lock to move the lock downwardly from locked tounlocked position when the retractor is swung upwardly on the pin f(Figs. 9 and 15). The bifurcated ends of the retractor are also providedwith a pair of cam faces 50 and 50' adapted to engage the faces 51 and51' of the receiver (Figs. 9 and 15) to retract the bolt slightly afterthe lock has reached unlocked posltion. The bolt may then be fullyretracted by pulling rearwardly on the retractor.

The retractor pin f is provided with a square head adapted to fit into asquare portion of the opening in the bifurcated ends of the retractor(Fig. 10) so that the pin rotates with the retractor. In its center thepin f is provided with a peripheral groove (Figs. 3, 10 and 15) intowhich the bead 52 (Fig. 17) on the retractor pin catch j is adapted toextend, the groove being provided with a depression adapted to receivethe head 52 when the retractor is in normal position. The catch y' isslidingly fitted in a longitudinal socket in the bolt, the upstandingend of the catch projecting through a slot 53 (Fig. 15) in the top ofthe bolt, and the catch is urged forwardly by spring is. The catch holdsthe retractor pin in place by virtue of the head 52 extending into theperipheral groove in the pin and the catch also holds the retractor innormal position by virtue of the bead 52 extending into the depressionin the peripheral groove.

The mechanism for rendering the gun safe after being cocked com rises asafety catch 8, a safety catch detent B, and a safety catch pivot Z, allshown in perspective in Fig. 17. The detent D is slidingly fitted intothe rear end of the same socket as retractor catch j above described,the detent having a lu extending upwardly into the slot 53 (Fig. 15) toprevent it from rotating in the socket. The detent has a pivot pinextending into in the forward end of the safety catch to hold the safetycatch in normal position, the detent bein yieldingly urged against theend of the sa ety catch by spring 7:: which also actuates the retractorcatch as above described. The safety catch is pivotally supported at itsrearward end by the pivot pin Z extending forwardl through the verticalportion 54 of the b0 t and thence into an axial socket in the rear endof the safety catch, the gin I being held in position by the tripperabove described. The forward end of the safety catch is provided with aneccentric head 55 which projects into the path of the striker when thecatch is rotated in a clockwise direction (Fig. 3) and the rearward endof the safety catch is provided with a finger-piece for rotating thecatch.

If the gun is uncooked the eccentric head 55 engages the periphery ofthe striker when it is attempted to rotate the catch into safetyposition thereby indicating that the gun is uncocked'. The rear face ofthe eccentric head 55 is slightly cammed so as to retract the strikeruntil the hooked end of the striker pin 37 disengages the cockingsleeve, whereby if the tripper T is depressed by pulling the triggerwhile the safety catch is in safe position there will be no danger ofthe hook on pin 37 catching in the axial opening in the cocking sleeveand failing to return to the position wherein it will hook over thecocking sleeve when the tripper returns to normal position. The hollowhandle of the retractor 1' when in normal position covers all of thesafety catch mechanism except the finger-piece 56.

In order more clearly to disclose the con- .struction of the firearmillustrated in the accompanying drawings the method of disassembling theparts will now be described. The catch a: is driven inwardly until itclears the trigger guard G and the trigger guard may then be slippeddownwardly out of the gun. The sight mount u; may then be slipped to therear off the receiver. After the sight mount w has been removed thebuffer key K is raised until the. buffer plunger N may he slippedforwardly out of the plunger mount M. The key K may then be slippedupwardly out of the receiver. The buffer mount M is then slippedrearwardly out of the receiver. The recoil springs Q may then he slippedrearwardly out of the receiver. v After first moving the lock Ldownwardly into unlocked position,

the bolt and all the parts carried thereby may then be slippedrearwardly out of the receiver, the transmitter T and T" fallinglatterly from the bolt.

To disassemble the bolt unit, the tripper spring e is withdrawnrearwardly through the slot in the bolt-hood 38 in which the spring ismounted. The trip r T is slipped downwardly out of the slot in the rearend of the bolt. The cocking sleeve a, striker Z, and striker spring dare then permitted to slide out of the rear end of the bolt. The

firing pin stop I) is slipped out of the bolt pivot l is withdrawn fromthe rear of the bolt and the safety catch detent D is pressed forwardlagainst the action of the spring k until it disengages the safety catcha, whereupon the safety catch may be removed from the bolt. The safetycatch detent D, spring K and retractor pin catch j may then be slippedrearwardly from the bolt. The extractor E is detached from the bolt byspringing the forward end upwardly until it clears the portion of thebolt which extends into the transverse slot in its lower face and thenpulling the extractor forwardly until itsrear cylindrical portion iswithdrawn from the socket 33 in the bolt.

To remove the stock from the receiver and barrel, the clip C is loosenedand slipped forwardly off the forward end of the stock, the shield 3slipping out of the dove-tailed guides in the top of the receiver as theclip is slipped forwardly. Thev cartridge magazine CM having beendetached from the gun as hereinbefore described, the stock The rear endof the trigger bar is then I pressed downwardly and the spring m isremoved. The trigger bar is then unhooked from its pivot pin. Thetripper pawl may then be slipped forwardly ofi the trigger bar afterfirst springing the hooked rearward end thereof downwardly until itclears the shoulder on the bottom of the trigger bar. To remove thebolt-stop Y and the ejector J, the upper .end of the bolt-stop spring7). is pressed downwardly below the level of the depending lugs onwasher W and the washer is then slipped rearwardly from the slot 44 inthe bottom of the ejector. The ejector and bolt-stop may then be slippedupwardly out of the receiver as a unit or the ejector may first beremoved and then the bolt-stop. After the stock has been removed themagazine catch shaft 11, to gether with the finger-piece 14 fastthereon, may be slipped out of the bearings 12 and 13, therebypermitting the catch 9 and spring 15 to drop out. To remove thelubricating mechanism the brackets 18 and 18' are dctached from thereceiver and the entire 111- bricating mechanism may then be removed.

The operation of the gun is as follows: \Vhen the gun is ready to firethe parts are in the positions illustrated in Figs. 3 and 10. \Vhen thetrigger is pulled the tripper T is moved downwardly until it engages thehook of striker pin 37 and unhooks the striker from the cocking sleeve0.. The striker Z is then plunged forwardly by the spring (1 until theforward end 36 strikes the firing "pin F and drives the firing pinforwardly against the primer of the cartridge in the firing chamber. Atthe instant offiring the parts occupy the positions shown in 12; i Vhenthe cartridge is fired the breech pressure is transmitted to thereceiver through the bolt head 27, thence to lock L, and thence .to thebearing plate P which is mounted on the oblique face of the receiverimmediately in the rear of the lock L.

Referring .now to Fig. 18 the lateral portions 22 and 22' of the lock Lbear against the plate P throughout the surfaces extending from thetransverse line 60 downwardly to the transverse line 61, the centraltrans verse portion 35 of the bearing plate (Fig. 13) extendingdownwardly only to the line 61. The lateral lugs 24: and 24' of the lockL bear against the legs 34: and 34' (Fig. 13*) of the bearing plate fromthe transverse line 62 downwardly to the transverse line 63. The obliquesurfaces 21 and 21 on the bolthead bear against the oblique forward-face of the portions 22 and 22 of the lock L from a transverse line 64downwardly to the trans verse line 65. The lock is so designed that thebearing surfaces of its opposite sides are symmetrically disposed withrespect to the plane 6667, which plane extends transversely of the pathof movement of the lock and makes equal angles a, a and b, b with saidbearing surfaces and which plane is perpendicular to the bisector of theangle between the forward and rearward faces of the lock and intersectsthe forward faces in the horizontal axial plane of the firing chamber,this plane being midway between the lines 64 and 65. With the bearingsurfaces thus arranged the breech pressure is-distributed uniformly overthe bearing surfaces between bearing plate over the surfaces extendingbetween lines 60 and 61 and half of the pressure being transmitted tothe bearing plate over the surfaces of the lugs 24 and 24' extendingbetween the lines 62 and 63. Owing to the wedge action of the lock L thepressure between the lock and the bearing plate will be greater than thepressure between the lock and the bolt-head, and the bearing surfaces atthe rear of the bolt are therefore preferably made larger in area sothat the pressure per unlit of area is the same on both sides of the b0t.

Owing to the fact that the forward and rearward faces of the lock areinclined at angles to the vertical differing from each other onlyapproximately four degrees, the rear face being inclined at the greaterangle, there is a tendency for the lock to be forced downwardly by thebreech pressure to unlock the bolt. However, this angle of four degreesis so small that the lock will not move downwardly while the breechpressure remains at a high value, but when the breech pressure hasdecreased to a relatively low value the lock is forced downwardlydirectly in response to the breech pressure, thereby unlocking the boltfrom the receiver according to the discovery disclosed in the aforesaidpatent to Blish. In this connection it is to be noted that the effectiveangle of the lock is determined largely by the magnitude of the breechpressure. The example chosen forthe purpose of illustration is an armyrifle firing standard cartridges which develop a breech pressure ofapproximately 52,000 pounds per square inch. In guns developing a lowerbreech pressure the effective angle wouldthe proper effective angle(four degrees in.

the present example).

After the breech pressure has dropped to a relatively low value and thelock is automatically moved downwardly until it clears the bearing plateP, the bolt and lock and other parts carried by the bolt are retractedby the breech pressure against the action of the recoil springs Q and Quntil the vertical portions of the rear face of the bolt strike theflange on the buffer plunger N, whereupon the excess momentum of thebolt is absorbed by the buffer. During the brief interval of timerequired for the lock L to move down into unlocked position thetransmitters T and T" are moved from the forward to the rearward end ofslot 39, thereby pushing the striker Z back out of contact with thefiring pin. The striker is thus prevented from contacting with thefiring pin until the lock is returned to locked position. During therecoil of the bolt the ejector J, which extends upwardly into the slotin the bottom of the bolt, ejects the cartridge case from its seat onthe bolt at the instant the forward face of the bolt passes the forwardedge of the ejector. During the recoil of the bolt the tubular portionof the buffer plunger N engages the rear face of the cooking sleeve 0and compresses the striker spring (1 until the hooked end of the strikerpin 37 has passed through the axial opening of the cocking sleeve andhooked over the rear face of the sleeve, the forward end of the tubularportion of the striker abutting against the rear faces of the inwardlypro- 'ecting fingers of the transmitters T and Afte(r1.the bol;. hals1reached its rearmoa.

'tion i '13 t e recoil springs 5123 Q returi the bolt to closedposition.

.During the forward movement of the bolt it feeds a cartridge from themagazine to the firing chamber in the usual manner. Also during theforward movement of the bolt, the ejector J engages the cocking sleeve 0and stops the forward movement of the striker and cocking sleeve, whichwere interlocked together on the recoil, before the bolt reaches closedposition, so that when Inasmuch as the recoil springs act on the boltthrough the transmitters T and T" and thence through the lock L,the'lock is automatically moved into locked position by the pressure ofthe recoil springs during the last interval of the forward stroke of thebolt, the forward obli ue faces of the lock engaging the oblique aces ofthe bolt and receiver respectively. The inner ends of the transmitters Tand T" which I roject into the slot 39 in the neck of the olt moveforwardly from the rearward to the forward end of this slot while thelock is moving into locked position and it is not until the lock hasreached a'safe locking position that the inner endsof the transmittershave advanced sufliciently to permit the striker to engage the firingpin. Thus it is impossible prematurely to fire the gun before the bolt1s safely locked.

When the magazine becomes empty the rear end 6 of the follower 5 liftsthe boltstop into the path of the bolt so that the bolt aaeaesa beforedescribed. The bolt may then be manually retracted by pulling rearwardlyon the retractor.

If it is desired to render the gun safe after it has been loaded andcocked, the safety catch 8 is rotated in a clockwise direction until theeccentric head 36 has moved downwardly into the path of the striker andforced the striker slightly to the rear as hereinbefore described.

What I claim is:

1. A gun comprising a frame, a breech block and a lock for locking saidblock in closed position, said lock being longitudinally movable in saidframe, and having opposite faces abutting faces of said frame and blockrespectively, and said block and frame faces being substantiallysymmetrically disposed relatively to a lane. extending transversely ofthe path 0 movement of the lock and making equal angles with said faces.

2. A gun comprising a frame, a breech block, and'a lock for locking saidblock in closed position, said lock b'ei longitudinally movable in saidframe, and hav1n opposite faces abuttin faces of said ame and blockrespective y, certain of said faces being so inclined to the line ofbreech pressure, and said block and frame faces being substantiallysymmetrically disposed relatively to a plane extendin transversely ofthe path of movement of t e lock and making elual angles with saidfaces.

3. gun comprisin a frame, a breech block, and a lock for focking saidblock' in closed position, said lock having opposite faces abuttingfaces of said franie and block respectively, the frame-lock andlock-block surfaces respectively making different angles with the lineof breech pressure, and said block and frame faces being substantiallysymmetrically disposed relatively to a plane extending transversely ofthe path of movement of the lock and making equal angles with saidfaces.

4. A gun comprisin a frame, a breech block, and a lock for ocking saidblockin closed position, said lock having opposite faces abutting facesofsaid frame and lock respectively, the frame-lock and lock-block facesmaking an angle with each other, and said faces being disposed smmetrically to a plane which is substantial y perpendicular to thebisector of said angle an sects said block-lock surfaces substantiallyin line with the axis of the breech pressure.

5. A gun comprising a breech closure, a lock for locking the breechclosure in closed position, said a lock being movable transversely ofthe line of breech pressure into and out of locking position, a firingpin, a striker, and means interposed between the lock and striker toobstructthe movement of the striker toward the firing pin when the lockis out of locked position thereby to prevent the gun from being firedexcept when the lock is in locked position.

6. A gun comprising a frame, a breech block, and a lock for locking saidblock in closed position, said lock having opposite faces abutting'faces of said frame and lock respectively, the frame-lock andlock-block faces making an angle with each other, and said faces beingdisposed symmetrically to a plane which is substantially perpendicularto the bisector of said angle.

1 '7. A gun comprising a breech block, a

lock for locking said breech block in closed position, said lock beingmovable transversely of said block into and out of locked position andwhen in unlocked position being movable withthe block, recoil springs onopposite sides of the block respectively,

transmitters interposed between said lock and said springs respectively,the parts being arranged so that the force of the recoil springs istransmitted to the block through the medium of the transmitters and thelock to move the block from open to closed position.

8. A gun comprising a breech block, a lock for locking said breech blockin closed position, said lock being movable obliquely forwardly intolocked position and when in unlocked position being movable with theblock, a recoil spring, a transmitter interposed between said lock andsaid spring, and firing mchanism on said block, said transmitter beingmovable longitudinally of said block as the lock moves obliquely intoand out of locking position and said transmitter being associated withsaid firing mechanism so as to prevent the gun from being fired exceptwhen the lock is in locked position.

9. A gun comprising a breech block, a lock.

for locking said breech block in closed position, said lock beingmovable obliquely forwardly into locked position and when in unlockedposition being movable with the block, recoil springs on opposite sidesof the block respectively, a transmitter interposed between said lockand said springs, and firing mechanism in said block, said transmitterbeing movable longitudinally of said block as the lock moves obliquelyinto and out of locking position and said transmitter having a portionextending into a longitudinal slot in the block in operativerelationship to said said block as the lock moves obliquely into and outof locking position and said transmitter being associated with saidstriker so as to prevent it from actuating the firing pin when the lockis in unlocked position.

11; A.- gun comprising a breech block, a lock for locking said breechblock in closed position, said lock being movable obliquely forwardlyinto locked position and when in unlocked position being movable withthe block, recoil springs on opposite sides of the block respectively, atransmitter interposed between said lock and springs, a firing pin insaid block, a striker arranged to strike said firing pin to fire thegun, said transmitter being movable longitudinally of said block as thelock moves obliquely into and out of locking position and saidtransmitter having a portion extending into a longitudinal slot in theblock in advance of a shoulder on the striker so as to prevent thestriker from actuating the firing pin when the lock is unlocked. v

12. A gun comprising a breech block, a lock for locking the breech blockin closed position, a firing pin in the breech block, a striker foractuating the firing pin, means for actuating the block and lock, and astop movable into the path of the striker by said means to prevent thestriker from actuating the firing pin when the lock is removed from thegun.

13. A gun comprising a breech block, a lock for locking the breech blockin closed position, a firing pin in the breech block, a.

stop transversely of t e block until the open-' ing therein is out ofalinement with the striker when the lock is removed from the gun so asto prevent the gun from being fired.

14. A gun comprising a semi-automatic breech block arranged to beretracted automatically, a bufi'er disposed behind the breech block toabsorb the excess recoil force mounted on the breech bl mechanism andmeans associated with said buffer for cooking said firing mechanism upontherecoil of the b f rising b hbl k 15. com a reec oc movable forw rldly aiid rearwardl into and out of breech clos' position, afiring membermovably moun on said block to move forwardly and rearwardly betweencocked and firing positions, a cocking member for latching the firingmember in cocked position, said member also being movably mounted onsaid block so as to be latched to said firing member, a spring intebetween said members for forcing t e firing member from cocked to firingposition when unlatched from the member, and means for restraining therearward movement of the cocking member duri the rearward movement ofsaid block to ri said members into latched relationship, an means forrestraining the forward movement of the latched members du the forwardmovement of said block to r' the said latched members into cockedposition.

16. A gun comprising a breech closure, firing mechanism asociatedtherewith, and means for automatically recocking the firin mechanismduring the periods the breec closure is opened and closed, said meansinof the breech block fi' 'cludinigman ejector for ejecting cartridgecases m the gun. 17. A gun comprising a semi-automatic breech closure,firing mechanism associated therewith and means for automaticallyrecocking t e firing mechanism during the opening and closing of thebreech closure,

said coc member also bei movably mounted on said block so as to latchedto said firing member, a ring inte d between saidmembers for orcing thering member from cocked to firing position when unlatched from thecocking member, means for, moving said cocking member relatively to saidblock into latchedrelationship wit said firing member during the openingmovement of the block, an ejector associated with the breech block forejecting cartridge cases,

said ejector being arranged to restrain movement of said members inlatched relationship relatively to said block during the closingmovement of the block. 7

19. A gun com rising a' frame, a breech bolt movable in t e frame, alock movable on said bolt, and a lever pivotally mounted on the bolt soas normally to lie alongthe bolt and so as to be swung out from thebolt, said lever havin cams adapted to engage said frame and ockrespectively when the lever is swung out to move the lock out of lockinposition and to retract the bolt.

20. gun comprising a breech block, a firi member movably mounted on thebreec block, means movably mounted on the block for' manually retractingthe block, means movably'mounted on the block for preventing said firiinto firing position, etents for respectively holding said two means inino rative position,'an d a single spring yiel ingly holdand a keyslidingly fitted into transverse ides in the rear of said buffer to holdit in position.

22. A gun comprising a frame, an automatic breech closure movable insaid frame,

a bufier in the rear of the breech closurefor abmrbing the recoil ofsaid closure, said bufier including a mount and a plunger fitted intosaid mount from the front and extending therethrough to the rear, and akey interlocking with said plunger to hold the mount and plunger inposition.

23. A gun comprising a frame, a cover over the rear end of said frame, abreech closure movable in said frame and cover, and a trigger guardarranged to lock said cover in position on the frame.

24. A gun comprising a frame, an automatic breech bolt, a bolt-sto meansfor antomatically moving said bol t-stop into position to hold said boltin retracted position after the last cartridge is fired, and an ejectorfor ejecting cartridge cases from the gun, said stop and ejector beinginterlocked in said frame.

Signed by me at Cleveland, Ohio, this twenty-fourth da of June 1919.

. IVER B. GRAHAM.

member from moving

